Patent GB-347682-A (GB)
Title: Improvements in or relating to the colouration of textile materials
Filed: 1930-01-28
Abstract: Vat dyes, dyeing with; cellulose esters or ethers, dyeing; regenerated celluloses, dyeing.-In colouring textile materials by vatting methods the vats are maintained at temperatures below the atmospheric, e.g. at 0-10 DEG C.  The process is particularly suitable for colouring materials liable to be damaged by alkaline media, e.g. materials made of or containing cellulose acetate or other organic derivatives of cellulose, regenerated celluloses, or animal fibres; it is applicable, for example, to the dyeing of cellulose acetate with indigoid dyes or with other vat dyes having affinity therefor.  Vat dyes specified as having affinity for cellulose esters but little affinity for cellulose fibres are Indanthrene orange RRK, Indanthrene pink B, Indanthrene yellow GK, Indanthrene reddish violet RH, Indanthrene orange 6RTK, Indanthrene grey 6B, Indanthrene golden orange G, Indanthrene brillant pink B, Indanthrene brilliant pink R, Algole pink B, Algole pink BG, Algole brown 5R, Algole rubine B, Algole scarlet GGR, Algole scarlet GGN, Algole red BB, Algole brilliant green BK, Hydron pink FF, Hydron pink FB, Hydron violet BBF, Hydron violet R, Hydron scarlet 3B, Hydron scarlet 2B, Hydron orange RF, Ciba yellow G, Ciba orange G, Ciba red R, Ciba red G, Ciba red 3B, Ciba scarlet G, Ciba pink R, Ciba pink BG, Ciba pink B, Ciba-brown 2R, Ciba brown G, Ciba violet 2R, Ciba violet B, Ciba violet R, Ciba violet 3B, Ciba helio B, Ciba bordeaux B, Ciba grey G, Ciba blue 2G, Ciba blue B, and Ciba indigo ciba R. Mixed materials may be coloured in contrasting or uniform shades according to the affinities of the several fibres for the dye or dyes used, and the colouration may be effected in a single bath or in successive baths one or both baths being an alkaline vat maintained at a temperature below the atmospheric.  Thus a mixture of cellulose acetate and cotton may be treated first in a vat maintained below atmospheric temperature and containing a vat dye having little or no affinity for cellulose acetate, to dye the cotton, and thereafter in a neutral or acid dyebath containing the free leuco compound of a vat dye as described in Specification 341,408, to dye the cellulose acetate; alternatively the cellulose acetate may be dyed by the methods of Specifications 219,349, 224,925, 242,393, 242,711, 269,960, 273,819, or 273,820, [all in Class 15 (ii), Dyeing, Processes &c. for].  Vat dyes specified as suitable for colouring the cotton or other cellulosic component of such a mixed material are Caledon brown R, Indanthrene orange RRT, Caledon yellow G, Caledon red 5G, Caledon jade green, Caledon blue GCD, and Caledon brilliant violet R.  The following examples are also specified; (1) A cotton-cellulose acetate fabric is dyed, the cotton blue and the cellulose acetate red, by treatment in an ice-cooled vat containing Indanthrene blue RK powder, caustic soda, and sodium hydrosulphite, allowing to oxidize in the air, and further treatment with 1 - amino - 4 - oxyanthraquinone by the process of Specification 219,349.  (2) A viscose-cellulose acetate fabric is dyed, the viscose red and the cellulose acetate blue, by first vat dyeing the viscose with Caledon red BN by the method used for the cotton in (1) and thereafter dyeing the cellulose acetate with the free leuco compound of Ciba blue 2B by the process of Specification 341,408.  (3) A cellulose acetate fabric is dyed blue by treatment in a vat, cooled to 10 DEG  C., containing Ciba blue 2B, caustic soda, and sodium hydrosulphite, followed by oxidation in the air.  The invention is also p  applicable to dyeing with sulphur dyes, and the strong alkali of the vats may be substituted by ammonia, amines, or the substances used for this purpose according to Specification 263,473, [Class 15 (ii), Dyeing, Processes &c. for].  The vat may also contain protective colloids.